In this R21 proposal, we address the hypothesis that knowledge of increased individual diabetes genetic risk will motivate patients with pre-diabetes to adopt and adhere to preventive lifestyle changes. Moreover, because genetic testing will also identify people with average or decreased relative risk, we will also examine the impact of "Lower Risk" testing results. We will adapt and extend existing multi- factorial genetic risk counseling approaches to the unique clinical problem of conveying complex disease genetic risk by creating a diabetes genetic risk counseling intervention. This intervention will be based on each subject's diabetes genotype risk score - a single aggregate score our team has developed that incorporates 18 currently identified diabetes risk genetic loci. To rigorously test the marginal impact of diabetes genotype testing compared to usual care, we will conduct a controlled trial among patients with pre-diabetes enrolled in a 12-session group-based lifestyle modification program for diabetes prevention. The specific aims of this proposal are to examine differences in perceived diabetes risk, diet- and exercise-specific motivation, and program attendance comparing subjects receiving an individual genotype risk counseling intervention to similar patients receiving usual care (controls). Preliminary results from this R21 and experience developing the genotype risk counseling intervention will be applied to the design of a subsequent larger-scale intervention evaluating the impact of diabetes genotype testing on clinical outcomes such as weight loss and diabetes prevention. RELEVANCE: The clinical practice of medicine is changing rapidly in this "dawn of the genomic era". With direct-to- consumer advertising by commercial companies and the eagerness with which many clinicians embrace new technology, it is imperative to establish the evidence base to guide the clinical application of genetic testing for common complex diseases such as type 2 diabetes. This R21 proposal will examine the impact on attitudes and behaviors in patients with pre-diabetes who are provided with their individual diabetes genotype risk score-a single score derived from aggregating the combined results of 18 diabetes risk-associated genetic loci.